Method of covering rollers



' C. G. WATSON METHOD OF COVERING ROLLERS Filed Sept. 1, 1938 2 Sheets-Sheet l IN VENTOR.

BY (9%,Moi5

ATTORNE 5.

Oct. 22, 1940- c, WATSON 2,219,085

, IMHO!) 0F 'covmnme ROLLERS Filed Sept. 1, 1938 2 Sheets-Sheet 2 iNVENTOR.

BY (7241-165 (1'. wzzzsorz, Mf

ATTORN 5.

ITO

Patented Oct. 22, 1940 UNITED STATES PATENT OFFICE 6 Claims.

metal having non-corrosive, or other particular characteristics.v Quite uniformly metals having such characteristics are of high price and often they are of a nature which make it difficult and expensive to form a shaft or roller entirely of such metal due to the difficulty of working same into the desired shape. 7 1

In forming a shaft or roller according to my invention I prepare of base metal, such as steel or cast iron, a shaft or roller of the shape desired and then bring to the full desired size by' applying a layer of metal which constitutes the working surface. The metal so forming the outside layer ..will be one which has the qualities and characteristics desired in such working surface.

For example, I have made a shaft roller for use in a Fourdrinier mill, which roller comprises a body portion, including end bearings, of steel, and having about the body portion, providing a working surface for the roller, a substantial layer of nickel compressed into such close relation with the body of the roll that it is immovable relative thereto. Such a roller has in use all of the properties of a nickel roller and may be prepared at a fraction of the cost of preparing a roller composed entirely of nickel or of any other metal having the desired characteristics.

To the accomplishment of the foregoing and related ends, said invention, then, consists of the means hereinafter fully described and particularlypointed out in the claims; the following description and the annexed drawings setting forth in detail one method and one product exemplifying my invention, such disclosed procedure and product constituting, however, but one of various applications of the principle of my invention.

In the drawings: 7

Fig. 1 shows a cross-sectional view of a roller constructed as taught herein; Fig. 2 is an elevational view of a sheet of nickel prepared for affixing on a roller; Fig. 3 is an elevational view of a roller assembled and held in a press for welding; Fig. 4 is a cross-sectional view of a roller of one type of my invention; Fig, 5 is a cross-sectional view of such a roller of another iypfittl igrfi is an elevational view of a roller with sheets so applied that the seams are obliquely disposed; Fig. 7 is a cross-sectional view of an assembly when covering a roller with a sheet in three parts, showing the relation of the compression jaws; and Fig. 8 is a sketch showing the position of the jaws when advancing by overlapping steps for the alternate welding of-the seams.

Referring to the drawings, a body portion I of a shaft or roller 2 is composed of steel which has been cast or otherwise formed in the shape desired. Said body portion I has bearing portions 3 integral therewith. About the circumferential surface of the main body which is the portion exposed to use in operations is a continuous sheet 4 of nickel of substantial thickness. Said sheet of nickel is in such intimate compressed relation with the steel of the body portion I that it may not be moved relative thereto without destroying same. Shafts, or rollers, similar to the one shown in Figs. 1 and 3 are adapted for use in Fourdrinier mills, glass lehrs and in a variety of construction" where it .would be exposed on its working surface to the destructive effects of chemicals, or where such surface might itself, if formed of steel or other unsuitable metal, have aninjurious effect upon the material being worked.

In forming such a shaft or roller, I turn down or otherwise finish the working -surface after the shaft or, roller has been cast or otherwise formed of the approximate size desired in the finished article. As a result of this finishing operation the working surface is such that, when a sheet of nickel or other metal of the desired thickness is applied thereto, the finished roller will be of the exact dimensions desired in use.

From metal sheets of the desired thickness portions are cut and so shaped that when placed with edges together they form a cylinder having on the inside the same diameter as was left in the roller after it was turned down or otherwise finished. These semi-cylindrical sheets 4 are assembled about the prepared body 2 and .the assembly placed in the jaws of a-hydraulic press 5, or similar device. The jaws of the press which receive the assembly are formed to the dimensions desired in the finished article. Extreme pressure is then applied to the jaws forcing the cylindrical sheets into intimate contact with the roller surface. The meeting edges 6 of the cylindrical' shells are tack welded together in the seams and the assembly is advanced across the, jaws of the press that successive sections may be compressed and tack welded. When successive tack welds 1 hold the entire length of the shells together, the seams 8 are each completely welded throughout their length. The weld metal, as it cools, draws the sheets into contact with the body of the roller closer than that resulting from the compressing force applied.

It readily appears that the sheets may be apsheets forming the surface layer.

lied in multiple with abutting edges 9, which may be welded. It is important that the longitudinal seams be secured by welding while the assembled parts are under compression, as in the press 5, or other device urging the sheets into intimate contact with the roller with the edges defining seams.

When affixing sheets of metal, as taught herein, on a hollow shaft, or a tubing, it is desirable to keep such shaft or tubing cool, as by flowing water therethrough. Also it may be advantageous in some cases to weld the seams 8 continuously while in the press, instead of tack welding therein and completing in a subsequent operation.

When it is desired that the metal of the weld seam be entirely free of contamination from the metal of the body portion of the roller, grooves l O'may be cut longitudinally in the body portion, which grooves will be so disposed that they will be located beneath the adjoining edges of the In these grooves strips ll of suitable metal, preferably that of the surface layer, will be placed and the sheets 4 will be so placed that their abutting edges will form a seam 8 over said strips 1 I. The assembly is then compressed as above explained and the edges of the sheets are welded to each other and to the underlying strips II, in the manner hereinabove set forth. On cooling, the metal melted in forming the welded seam will contract and the tension of such contraction will draw the sheets into contact with the body portion closer than that resulting from the compressive force of the press 5. Seams so formed will be uncontaminated by the metal of the roller body.

While I have indicated herein a preference for a hydraulic press as a means of applying the pressure needed to force the surface sheets into intimate contact with the body of the roller, it is within the scope of my invention to weld the seams while passing the assembly continuously between grooved compression rollers, or otherwise securing the indicated compression for the sheets and roller during the welding steps.

Also, as indicated, the shaft or other article to be clad with a special metal as taught herein may be tubular if desired, and the method of my invention may be used in applying sheets of metal other than nickel to shafts of metal other than iron. Stainless steel and Monel metal are particularly adapted for use in. making noncorrosive shafts. Also it is apparent that the strips ll placed in the grooves ill need not be of the same metal as that of the applied sheets. For example, strips of Monel metal may be used in the grooves when sheets of nickel are being applied to a steel shaft.

In some applications it may be desirable to have the weld seams run diagonally or out of parallel with the axis of the shaft. It is not essential that the two seams be diametrically disposed and accordingly one of the applied sheets may be larger than the other, or three or more sheets may be used to cover the circumferential surface of a roller or shaft. Such diagonal seams are particularly desirable when a roller is to be used with a doctor blade or the like. The weld metal of the seams is apt to differ from the body metal of the sheet covering in respect to hardness. When such aseam is parallel to the axis of the roller, such a doctor blade will strike it for the full length at the same instant, which may result in wearing at the seams or even gouging. By disposing such seams at slight angles to what they would be if parallel to the roller axis the doctor blade at any moment will contact the seam at only one spot and the seam will wear down evenly with the restof the roll. For similar reasons the circumferential seams when used may be placed at an anglewith a true circumference of the roller.

In Fig. 6 the seam 3| is obliquely disposed with the above stated object, and similarly the circumferential seams 32 and 3'3 are for the. Same reason obliquely disposed. These seams are welded in the same manner as are the seams which are not at an oblique angle.

When it is desired to form the surface covering with more than two longitudinal shells, the jaws of the press may be so disposed that one is provided for each segment of the covering. In Fig. '7 these jaws are shown compressing three segments! the edgesof which form the seams 8. These three seams may be all welded between the jaws at each advance thereof, or they will preferably be welded bystaggered welding of one seam during each compression.

The best results are secured, when covering a large size roller, by using a staggered welding of the seams. In this method, one seam is welded the full width of the jaws, as the operation is initiated at one end of the roller, and the other seams are welded proportionate lengths between such jaw, that is to say when using two seams the second will be welded for one half such length, and when using three seams the second will be welded two-thirds of the jaw length and the third will be welded one-third. Then the roller assembly is shifted through the jaws until they embrace the section of the assembly immediately adjacent the shortest welded seam. In this position the assembly is compressed and in the seam having the shortest weld the seam is welded for the full width of the jaws. The assembly is then shifted until the jaws embrace the section adjacent the end of the welded seam which is now the shortest. This operation is repeated until all seams have been fully welded.

In Fig. 8 is shown the steps of the staggered welding as applied with two seams. Referring thereto, jaws of a length equal to the section ac in said figure will first compress the roll I with its assembled covering sheets in the section between a-c and a--c. The seams ab and a--c' will be welded. The jaws will then be advanced to positions b-d and b'-d' and compressed, and the seam 'b-d will be welded; the jaws will then be advanced to the positions.c-e and c'e' and compressed, and the seam c'-e' welded; the jaws will then be advanced to positions d--f and d'f' and the seam d-l will be welded. These steps will be continued until the jaws compress the end sections f--h and f'-h' in which position the seams fh and g'h will be welded.

In the practice of my invention welds, uniting the sheets into an integral covering, are formed, while the said sheets are compresed about the body member. These welds exert, on cooling, the tension desired to draw said integral covering into intimate relation with said body member. The well understood contraction of weld metal is used in my invention in a novel relation for securing a novel metal clad article having a wide variety of uses, since it has the desired characteristics of old articles which can be produced only at a substantially greater cost.

When desired, my invention may be used when completely covering the surface of a roller or the like. Referring to Fig. 1, the left-hand end of the roller shown in cross-section illustrates the means of so covering. After applying the surface covering 3 as explained, a covering member 2| may be similarly applied to the bearing 3. Then a washer-shaped member 22 is fitted about the said bearing 3 and welded to the coverings 4 and 2!. Then a circular member i3 is fitted on the end of the bear ng 3 and welded to the covering 2|. These members 2!, 22 and 23 will preferably be of material similar to that of the roller covering l, but may be of other sheet metal having desired characteristics.

Similarly, limited areas of the surface of a roller or shaft may be covered as taught herein' and the uncovered portion may be coated with other material, such as rubber or other non-metallic covering.

Other modes of applying the principle of my invention may be employed instead of the one explained, change being made as regards the product and method herein disclosed, provided the step or steps stated by any of the following claims or the equivalent of such stated step or steps be employed.

I therefore particularly point out and distinctly claim as my invention:

1. The method of covering a roller with a sheet of metal comprising the following steps, assembling about a desired length of such roller semicylindrical shells of sheet metal; compressing a section of the assembly, thereby made, into intimate contact between jaws, cut approximately to the curvature desired in the covered roller, while maintaining the longitudinally disposed seams, formed by the adjacent edges of suchshells, in registry with openings between such jaws; by Welds, joining the edges so forming one seam for the length of the portion thereof included in such an opening; by welds, joining the edges forming the other seam for a partial length of the portion so included in an opening of such jaws; re-setting such jaws adjacent the shorter of the welded seams; compressing such assembly into intimate contact; by weld, joining, in such seam having the shorter welded portion, the edges for the length of the portion of the seam within the opening of such jaws; and repeating, resetting the jaw sequentially just beyond the welded seam which successively is the shorter, and then by welds joining the edges in such seam for a section thereof having the length of such laws.

2. The method of covering a roller with a sheet of metal comprising the following steps, assembling about a desired length of such roller longitudinal shells of sheet metal which together completely cover such length; compressing a section of the assembly thereby made into intimate contact, between jaws cut approximately to the curvature desired in the covered roller, while.

maintaining the longitudinally disposed seams, formed by adjacent edges of such shells, in registry with openings between such jaws; by welds joining the edges so forming one such seam for the length of the portion thereof included in such an opening; by welds joining the edges forming such other scams for partial lengths of the portion in the openings between such jaws; re-setting such jaws adjacent the shortest welded seam; compressing such assembly into intimate contact; by welds joining the edges, in such seam having the shortest welded seam, for the length of the portion of such seam included between such jaws when in such advanced position; and repeating, advancing the same sequentially to a position just beyond the welded seam which successively is the shortest, and then by welds joining the edges in such seam for a section thereof having the length of such jaws, until the edges of all seams are for their full length joined by Welds.

3. The method of coating a roller with a layer of metal comprising the following steps, forming a plurality of shells of sheet metal each of which when curved, conform to a segment of the circumferential surface of the roller, and all of which completely cover a desired portion thereof with adjacent edges defining seams which are obliquely disposed relative to the axis of such roller; assembling such shells about such roller; compressing successive longitudinal sections of such assembly between jaws, cut to approximately the curvature desired in the finished roller, until shells and roller are in. intimate contact moving said jaws, in compressing, radially of the roller and toward each other; and while so compressed welding sections of longitudinally disposed seams as such sections are successively enclosed between such jaws. V

4. In covering a roller and the like with a sheet of metal by welding longitudinal seams between metal sheets, together covering a length of such roller, while such sheets are compressed radially in successive over-lapping sections into intimate contact with such roller; the step which comprises welding in rotation sections of the several seams by successively welding one such seam, for

the length thereof included in each such compressed section, as the sheets are progressively compressed in sections over-lapping axially; whereby the welded portion of each such seam is extended alternately in advance of any other seam.

5. The method of coating a metallic roller with a layer of metal, which comprises forming a plurality of cylindrical segmental shells of sheet metal of such size as will together. cover a desired longitudinal portion of such roller; assembling such roller and such shells with proximate edges of the latter forming seams longitudinally disposed; placing successive sections of such assembly between jaws cut to the curvature desired in the finished roller; in each such section moving such jaws together radially of such roller with a pressure suflicient to force such shells into intimate contact with such roller; and welding the abutting edges together in such seams between such jaws while under such pressure.

6. In a method of applying a cover sheet of thin metal about a roller and the like by welding axially disposed seams between metal sheets, assembled together and covering an axially disposed length of such roller, the improvement including the following steps: compressing successive overlapping longitudinal sections, of such sheets so assembled, radially into intimate contact with the covered roller; successively welding connecting limited sections of one such seam while the sheets are under such compressions; and, in alternation with such welding of scam sections, welding in another seam, while under such compressions, similar sections which are overlapping in relation to such sections in the first named seam. l

CHARLES G. WATSON. 

